I have long been a proponent of the use of body scanners at airport security checkpoints. Those with bad intent can inflict significant damage with items that simply cannot be detected by traditional metal detection technology.

Profiling techniques can help intelligently determine what kind of technology to use on which passenger.

The archways we routinely walk through at airports cannot detect weapons made of wood, glass, ceramic, or carbon, let alone explosives of any kind. So, while we may view body scanners as an invasion or privacy, they are a necessary evil.

That said, I believe that the mass roll-out of body scanners is a total waste of money. First of all, the body scanners based on millimeter wave and backscatter X-ray technology can only see beneath the clothing but cannot see through the body. Customs authorities around the globe are purchasing transmission X-ray systems which can detect internal concealments.

Drug traffickers transport their illicit cargo through internal carries, so it is only a matter of time before the aviation industry is targeted in such a manner. It should be noted that customs authorities (and their immigration counterparts) find people doing something wrong every day after they get off an aircraft — even though they only actually screen a very small percentage of arriving passengers. We need to deploy some of these customs processes and technologies to identify threat passengers before they board.

We need to have checkpoints with a range of available technologies. The passenger should not know in advance which technology will be used to screen them. Most passengers should be screened by traditional metal detectors, but those we have concerns about — as a result of their appearance, behavior or documentation — should be screened with body scanners. I would be happy for certain passengers — those we know are not a threat (and not just because they are frequent flyers!) — not to be screened at all.

Ultimately, what we need to deploy at the checkpoint is common sense. The fact is, the current reactive approach to aviation security, the continued adding-on of new technologies and the check-box approach to screening does not work.

The challenge for American authorities is countering emotionally charged concerns over the use of profiling. Profiling techniques are used at airports by every other security agency with great success. It can help determine, intelligently, which technology to use on which passenger.